Method and devices for cutting tissue

ABSTRACT

A method of removing material from a blood flow lumen generally includes providing a device having a cutting element and an opening, advancing the device through the blood flow lumen to a site where material is to be removed, forcing the opening toward a wall of the site where material is to be removed, and moving the cutting element and the opening so that material in the blood flow lumen is cut by the cutting element and directed into the opening for removal as the cutting element and opening are moved through the blood flow lumen. In some embodiments, the device may be deflected or bent to force the opening toward a wall to remove material. The cutting element may be rotatable and may have an axis that is movable, that is not parallel to the longitudinal axis of the device, or both. In some embodiments, the cutting element is movable between retracted and deployed positions for advancing the device to a site for treatment and for removing material, respectively.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 10/288,581, filed Nov. 4, 2002, which is acontinuation-in-part of U.S. patent application Ser. No. 10/027,418,filed Dec. 19, 2001, entitled “Debulking Catheter”, which claims thebenefit of Provisional Patent Application Ser. No. 60/257,704, filedDec. 20, 2000, entitled “Debulking Catheter” and Provisional PatentApplication Ser. No. 60/272,273 filed Feb. 27, 2001, entitled “DebulkingCatheter”, the complete disclosures of which are incorporated herein byreference.

The present application is also related to U.S. patent application Ser.No. 09/377,884, filed Aug. 19, 1999, now U.S. Pat. No. 6,638,233,entitled “Apparatus and Methods for Material Capture and Removal” andSer. No. 09/377,894, filed Aug. 19,1999, now U.S. Pat. No. 6,447,525,entitled “Apparatus and Methods for Removing Material From a BodyLumen,” the complete disclosures of which are incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to systems and methods fordebulking body lumens. More particularly, the present invention relatesto atherectomy catheters for excising atheroma and other materials fromblood vessels and from stents.

Cardiovascular disease frequently arises from the accumulation ofatheromatous material on the inner walls of vascular lumens,particularly arterial lumens of the coronary and other vasculature,resulting in a condition known as atherosclerosis. Atherosclerosisoccurs naturally as a result of aging, but may also be aggravated byfactors such as diet, hypertension, heredity, vascular injury, and thelike. Atheromatous and other vascular deposits restrict blood flow andcan cause ischemia which, in acute cases, can result in myocardialinfarction. Atheromatous deposits can have widely varying properties,with some deposits being relatively soft and others being fibrous and/orcalcified. In the latter case, the deposits are frequently referred toas plaque.

One conventional treatment for cardiovascular disease is the use ofstents. Endoluminal stents are commonly used to treat obstructed orweakened body lumens, such as blood vessels and other vascular lumens.Once deployed in the blood vessel, the stent can remain in the bodylumen where it will maintain the patency of the lumen and/or support thewalls of the lumen which surround it. One factor impeding the success ofstent technology in endoluminal treatments is the frequent occurrence ofin-stent restenosis, characterized by proliferation and migration ofsmooth muscle cells within and/or adjacent to the implanted stent,causing reclosure or blockage of the body lumen.

Atherosclerosis and restenosis can be treated in a variety of ways,including drugs, bypass surgery, and a variety of catheter-basedapproaches which rely on intravascular debulking or removal of theatheromatous or other material occluding a blood vessel. Of particularinterest to the present invention, a variety of methods for cutting ordislodging material and removing such material from the blood vesselhave been proposed, generally being referred to as atherectomyprocedures. Atherectomy catheters intended to excise material from theblood vessel lumen generally employ a rotatable and/or axiallytranslatable cutting blade which can be advanced into or past theocclusive material in order to cut and separate such material from theblood vessel lumen. In particular, side-cutting atherectomy cathetersgenerally employ a housing having an aperture on one side, a blade whichis rotated or translated by the aperture, and a balloon to urge theaperture against the material to be removed.

Although atherectomy catheters have proven very successful in treatingmany types of atherosclerosis and in-stent restenosis, improvedatherectomy catheters and methods are continuously being pursued. Forexample, many currently available side-cutting atherectomy cathetershave difficulty in capturing occluding material in the cutting aperture.To facilitate material capture, the cutting aperture is frequentlyelongated to increase the area into which the material can penetrate.Such elongation typically requires an equivalent lengthening of thecutter housing. Since most cutter housings are rigid, such lengtheningmakes it more difficult to introduce the distal end of the catheterthrough tortuous regions of the vasculature.

Another shortcoming of many currently available atherectomy catheters isthat they typically require a balloon positioned opposite the cuttingwindow to urge the cutting window into contact with occluding material.Such balloons, however, unduly increase the size of the distal portionof the catheter. Even with the balloon, the amount of material that canbe removed by conventional atherectomy catheters is limited by the sizeof the cutting window. Other disadvantages of some catheters includecutting elements with less than ideal hardness, inadequate storage spacewithin the catheter for containing removed material, sub-optimal guidewire lumens, and/or the like.

For these reasons, it would be advantageous to have atherectomycatheters, and methods for their use, which could access small, tortuousregions of the vasculature and remove atheromatous and other occludingmaterials from within blood vessels and stents in a controlled fashion.In particular, it would be desirable to have atherectomy catheters andmethods which could facilitate capturing and invagination ofatheromatous materials. Ideally, such catheters and methods would beadaptable for use in a variety of body lumens, including but not limitedto coronary and other arteries. At least some of these objectives willbe met by the present invention.

BRIEF SUMMARY OF THE INVENTION

The present invention provides catheters and methods for removingmaterial from (or “debulking”) a body lumen. Catheters of the presentinvention may be used in a variety of body lumens, including but notlimited to intravascular lumens such as coronary arteries. Typically,debulking catheters are used to remove occlusive material, such asatherosclerotic plaque, from vascular lumens, but they may alternativelybe used to remove other materials. Generally, debulking cathetersinclude a proximal portion, a distal portion having an opening (or“window”), and a cutting element (or “tissue debulking assembly”) whichmay be exposed through the opening to contact material in a body lumen.The catheter debulks a body lumen when it is moved while the cuttingelement is in contact with the material in the lumen.

In one aspect of the present invention, a method of removing materialfrom a blood flow lumen comprises: providing a device having a cuttingelement and an opening; advancing the device through the blood flowlumen to a site where material is to be removed; forcing the openingtoward a wall of the site where material is to be removed; and movingthe cutting element and the opening after the forcing step so thatmaterial in the blood flow lumen is cut by the cutting element anddirected into the opening for removal as the cutting element and openingare moved through the blood flow lumen. Optionally, the moving step maybe carried out with the cutting element and the opening moving togetherin unison through the blood flow lumen.

In some embodiments, the forcing step is carried out by bending thedevice so that the opening is forced against the wall of the site. Alsoin some embodiments, the providing step is carried out with the cuttingelement being rotatable, with the moving step being carried out with thecutting element rotating when severing the material. When the cuttingelement is rotatable, the providing step may be carried out with thedevice having a longitudinal axis, and with the moving step beingcarried out with the cutting element rotating around an axis which isnot parallel to the longitudinal axis of the device. In someembodiments, the providing step is carried out with the cutting elementhaving an axis of rotation which is movable relative to a longitudinalaxis of the device.

In some embodiments, the moving step is carried out with the cuttingelement cutting a continuous piece of material. Optionally, in suchembodiments, the providing step may be carried out with the openingbeing on a side of the device; the forcing step may be carried out toforce the side against the blood flow lumen; and the moving step may becarried out with the cutting element extending out of the opening, thecutting element directing the continuous piece of material into theopening. In some embodiments, the moving step is carried out by movingthe cutting element and window in a distal direction, with the cutmaterial being stored in the device at a location distal to the cuttingelement. Also in some embodiments, the providing step is carried outwith the cutting element being movable relative to the opening.

In still other embodiments, the providing step is carried out with thecutting element being movable between a deployed position and aretracted position, the cutting element extending out of the openingwhen in the deployed position and being contained within the openingwhen in the retracted position. In such embodiments, the advancing stepis typically carried out with the cutting element in the retractedposition and the moving step is carried out with the cutting elementbeing in the deployed position. For example, the providing step may becarried out with the cutting element extending beyond the opening adistance of about 0.025 mm to about 0.64 mm. Generally, the providingstep may be carried out with the opening being positioned along a sideof the device.

In still another aspect of the present invention, a device for cuttingtissue is provided which has an elongate body with an opening therein. Arotatable cutting element is coupled to a torque transmitting elementwhich extends through the body. A visualization element is movable froma stored position to a working position which is at a radially outwardposition on the body.

In yet another aspect of the present invention, a device for cuttingtissue is provided which has a movable cover coupled to the body. Thecover is movable from a stored position, in which the rotatable cuttingelement is covered by the cover, to a working position, in which atleast part of the rotatable cutting element is exposed. The cover may belinearly movable relative to the body so that the cover essentiallytranslates without deforming.

In another aspect of the invention, a method of removing material from avascular location is provided. The body may be deformed before advancingthe cutting element and opening through the vascular region to cut andremove a continuous piece of material as describe herein. The deformableportion of the body may take any suitable shape such as S-shaped orhelical providing the step of forcing the opening toward a wall of thesite where material is to be removed. The deformable portion may berelatively long, such as at least 1 cm or even at least 2 cm, to helpstabilize the device.

In another aspect of the invention, a device for cutting tissue isprovided which has two pivot points on opposite sides of the cuttingelement. The pivot points both help to move the cutting element into thecutting position and force the opening toward a wall. In particular thecutting or working position presents the cutting element at anorientation which may be advantageous when advancing the entire devicethrough the vasculature as describe herein to cut and remove acontinuous piece of material.

For a further understanding of the nature and advantages of theinvention, reference should be made to the following description takenin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a debulking catheter of the presentinvention;

FIG. 1A is a side view of a portion of a debulking catheter as in FIG.1, where the body has a rigid distal portion with a bend, according toone embodiment of the present invention;

FIG. 2 is an exploded view of an exemplary distal portion of thedebulking catheter of the present invention;

FIG. 3A is an end view of the distal portion of the debulking catheterof FIG. 1 in which the cutter is in a closed position in the catheterbody;

FIG. 3B is a sectional view along Line A-A of FIG. 3A;

FIGS. 3C and 3D are views of the distal portion of a debulking catheter,where the distal portion has a locking shuttle mechanism;

FIG. 4A is an end view of the distal portion of the debulking catheterof FIG. 1 in which the cutter is in an open position outside of thecutting window;

FIG. 4B is a sectional view along Line A-A of FIG. 4A;

FIGS. 4C and 4D are views of the distal portion of a debulking catheter,where the distal portion has a locking shuttle mechanism;

FIG. 5A is an end view of the distal portion of the debulking catheterof FIG. 1 in which the cutter is in a packing position within a tip ofthe catheter;

FIG. 5B is a sectional view along Line A-A of FIG. 5A;

FIGS. 6 to 8 illustrate a monorail delivery system of the presentinvention;

FIG. 9A is a perspective view of a cutter of the present invention;

FIG. 9B is an end view of the cutter of FIG. 9A;

FIG. 9C is a sectional view of the cutter along Line A-A of the cutterof FIGS. 9A and 9B;

FIG. 10A is a perspective view of a in-stent restenosis cutter of thepresent invention;

FIG. 10B is an end view of the cutter of FIG. 10A;

FIG. 10C is a sectional view of the cutter along Line B-B of the cutterof FIGS. 10A and 10B;

FIG. 11A is a perspective view of another in-stent restenosis cutter ofthe present invention;

FIG. 11B is an end view of the cutter of FIG. 11A;

FIG. 11C is a sectional view of the cutter along Line C-C of the cutterof FIGS. 11A and 11B;

FIG. 11D is a side view of another embodiment of a cutter, shownpartially within a catheter body;

FIG. 12 illustrates a proximal handle and cutter driver of the presentinvention;

FIG. 13 illustrates a cutter driver with a handle cover removed;

FIGS. 14 to 16 illustrate three positions of the lever for controllingthe cutter;

FIG. 17 is a simplified flow chart illustrating a method of the presentinvention;

FIGS. 18 and 19 illustrate a method of the present invention;

FIG. 20 schematically illustrates another method of the presentinvention

FIG. 21 shows another device for cutting tissue with the device having amovable cover;

FIG. 22 shows the device of FIG. 21 with the cover in a stored position;

FIG. 23 shows the device of FIG. 21 with the cover in a working positionwhich exposes part of the rotatable cutting element;

FIG. 24 shows still another device for cutting tissue having two pivotpoints on opposite sides of the cutting element;

FIG. 25 shows the device of FIG. 24 after articulating the device at thepivot points to put the cutting element in a cutting position;

FIG. 26A is a side view of the elongate body or shaft forming a helicalshape.

FIG. 26B is a perspective view looking at the distal end of the device;

FIG. 27A shows a tube which forms part of the elongate body of FIG. 26in a straight configuration;

FIG. 27B shows the tube of FIG. 27A in a bent configuration; and

FIG. 28 illustrates a kit of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The catheters and methods of the present invention are designed todebulk atheroma and other occlusive material from diseased body lumens,and in particular coronary arteries, de novo lesions, and in-stentrestenosis lesions. The catheters and methods, however, are alsosuitable for treating stenoses of body lumens and other hyperplastic andneoplastic conditions in other body lumens, such as the ureter, thebiliary duct, respiratory passages, the pancreatic duct, the lymphaticduct, and the like. Neoplastic cell growth will often occur as a resultof a tumor surrounding and intruding into a body lumen. Debulking ofsuch material can thus be beneficial to maintain patency of the bodylumen. While the remaining discussion is directed at debulking andpassing through atheromatous or thrombotic occlusive material in acoronary artery, it will be appreciated that the systems and methods ofthe present invention can be used to remove and/or pass through avariety of occlusive, stenotic, or hyperplastic material in a variety ofbody lumens.

Apparatus according to the present invention will generally comprisecatheters having catheter bodies adapted for intraluminal introductionto the target body lumen. The dimensions and other physicalcharacteristics of the catheter bodies will vary significantly dependingon the body lumen which is to be accessed. In the exemplary case ofatherectomy catheters intended for intravascular introduction, theproximal portions of the catheter bodies will typically be very flexibleand suitable for introduction over a guidewire to a target site withinthe vasculature. In particular, catheters can be intended for“over-the-wire” introduction when a guidewire channel extends fullythrough the catheter body or for “rapid exchange” introduction where theguidewire channel extends only through a distal portion of the catheterbody. In other cases, it may be possible to provide a fixed or integralcoil tip or guidewire tip on the distal portion of the catheter or evendispense with the guidewire entirely. For convenience of illustration,guidewires will not be shown in all embodiments, but it should beappreciated that they can be incorporated into any of these embodiments.

Catheter bodies intended for intravascular introduction will typicallyhave a length in the range from 50 cm to 200 cm and an outer diameter inthe range from 1 French to 12 French (0.33 mm: 1 French), usually from 3French to 9 French. In the case of coronary catheters, the length istypically in the range from 125 cm to 200 cm, the diameter is preferablybelow 8 French, more preferably below 7 French, and most preferably inthe range from 2 French to 7 French. Catheter bodies will typically becomposed of an organic polymer which is fabricated by conventionalextrusion techniques. Suitable polymers include polyvinylchloride,polyurethanes, polyesters, polytetrafluoroethylenes (PTFE), siliconerubbers, natural rubbers, and the like. Optionally, the catheter bodymay be reinforced with braid, helical wires, coils, axial filaments, orthe like, in order to increase rotational strength, column strength,toughness, pushability, and the like. Suitable catheter bodies may beformed by extrusion, with one or more channels being provided whendesired. The catheter diameter can be modified by heat expansion andshrinkage using conventional techniques. The resulting catheters willthus be suitable for introduction to the vascular system, often thecoronary arteries, by conventional techniques.

The distal portion of the catheters of the present invention may have awide variety of forms and structures. In many embodiments, a distalportion of the catheter is more rigid than a proximal portion, but inother embodiments the distal portion may be equally as flexible as theproximal portion. One aspect of the present invention provides cathetershaving a distal portion with a reduced rigid length. The reduced rigidlength can allow the catheters to access and treat tortuous vessels andsmall diameter body lumens. In most embodiments a rigid distal portionor housing of the catheter body will have a diameter that generallymatches the proximal portion of the catheter body, however, in otherembodiments, the distal portion may be larger or smaller than theflexible portion of the catheter.

A rigid distal portion of a catheter body can be formed from materialswhich are rigid or which have very low flexibilities, such as metals,hard plastics, composite materials, NiTi, steel with a coating such astitanium nitride, tantalum, ME-92®, diamonds, or the like. Most usually,the distal end of the catheter body will be formed from stainless steelor platinum/iridium. The length of the rigid distal portion may varywidely, typically being in the range from 5 mm to 35 mm, more usuallyfrom 10 mm to 25 mm, and preferably between 6 mm and 8 mm. In contrast,conventional catheters typically have rigid lengths of approximately 16mm.

The side opening windows of the present invention will typically have alength of approximately 2 mm. In other embodiments, however, the sideopening cutting window can be larger or smaller, but should be largeenough to allow the cutter to protrude a predetermined distance that issufficient to debulk material from the body lumen.

The catheters of the present invention can include a flexible atraumaticdistal tip coupled to the rigid distal portion of the catheter. Forexample, an integrated distal tip can increase the safety of thecatheter by eliminating the joint between the distal tip and thecatheter body. The integral tip can provide a smoother inner diameterfor ease of tissue movement into a collection chamber in the tip. Duringmanufacturing, the transition from the housing to the flexible distaltip can be finished with a polymer laminate over the material housing.No weld, crimp, or screw joint is usually required.

The atraumatic distal tip permits advancing the catheter distallythrough the blood vessel or other body lumen while reducing any damagecaused to the body lumen by the catheter. Typically, the distal tip willhave a guidewire channel to permit the catheter to be guided to thetarget lesion over a guidewire. In some exemplary configurations, theatraumatic distal tip comprises a coil. In some configurations thedistal tip has a rounded, blunt distal end. The catheter body can betubular and have a forward-facing circular aperture which communicateswith the atraumatic tip. A collection chamber can be housed within thedistal tip to store material removed from the body lumen. Thecombination of the rigid distal end and the flexible distal tip isapproximately 30 mm.

A rotatable cutter or other tissue debulking assembly may be disposed inthe distal portion of the catheter to sever material which is adjacentto or received within the cutting window. In an exemplary embodiment,the cutter is movably disposed in the distal portion of the catheterbody and movable across a side opening window. A straight or serratedcutting blade or other element can be formed integrally along a distalor proximal edge of the cutting window to assist in severing materialfrom the body lumen. In one particular embodiment, the cutter has adiameter of approximately 1.14 mm. It should be appreciated however,that the diameter of the cutter will depend primarily on the diameter ofthe distal portion of the catheter body.

In exemplary embodiments, activation of an input device can deflect adistal portion of the catheter relative to the proximal portion of thecatheter. Angular deflection of the distal portion may serve one or morepurposes in various embodiments. Generally, for example, deflection ofthe distal portion increases the effective “diameter” of the catheterand causes the debulking assembly to be urged against material in alumen, such as atherosclerotic plaque. In other embodiments, deflectionof the distal portion may act to expose a debulking assembly through awindow for contacting material in a lumen. In some embodiments, forexample, activation of the input device moves the debulking assemblyover a ramp or cam so that a portion of the rigid distal portion andflexible tip are caused to drop out of the path of the debulkingassembly so as to expose the debulking assembly through the window. Insome embodiments, deflection may both urge a portion of the catheterinto material in a lumen and expose a tissue debulking assembly.

Some embodiments further help to urge the debulking assembly intocontact with target tissue by including a proximal portion of thecatheter body having a rigid, shaped or deformable portion. For example,some embodiments include a proximal portion with a bend that urges thedebulking assembly toward a side of the lumen to be debulked. In otherembodiments, one side of the proximal portion is less rigid than theother side. Thus, when tension is placed on the catheter in a proximaldirection (as when pulling the debulking assembly proximally for use),one side of the proximal portion collapses more than the other, causingthe catheter body to bend and the debulking assembly to move toward aside of the lumen to be debulked.

In exemplary embodiments, the debulking assembly comprises a rotatablecutter that is movable outside the window. By moving the cutter outsideof the cutting window beyond an outer diameter of the distal portion ofthe catheter, the cutter is able to contact and sever material that doesnot invaginate the cutting window. In a specific configuration, therotating cutter can be moved over the cam within the rigid, or distal,portion of the catheter body so that the cutting edge is moved out ofthe window. Moving the rotating cutter outside of the cutting window andadvancing the entire catheter body distally, a large amount of occlusivematerial can be removed. Consequently, the amount of material that canbe removed is not limited by the size of the cutting window.

As will be described in detail below, in some situations it ispreferable to provide a serrated cutting edge, while in other situationsit may be preferable to provide a smooth cutting edge. Optionally, thecutting edge of either or both the blades may be hardened, e.g., byapplication of a coating. A preferred coating material is a chromiumbased material, available from ME-92, Inc., which may be appliedaccording to manufacturer's instructions. In some embodiments, thecutter includes a tungsten carbide cutting edge. Other rotatable andaxially movable cutting blades are described in U.S. Pat. Nos.5,674,232; 5,242,460; 5,312,425; 5,431,673; and 4,771,774, the fulldisclosures of which are incorporated herein by reference. In someembodiments, a rotatable cutter includes a beveled edge for removal ofmaterial from a body lumen while preventing injury to the lumen. Instill other embodiments, a tissue debulking assembly may includealternative or additional features for debulking a lumen. For example,the debulking assembly may include, but is not limited to, a radiofrequency device, an abrasion device, a laser cutter and/or the like.

The catheters of the present invention may include a monorail deliverysystem to assist in positioning the cutter at the target site. Forexample, the tip of the catheter can include lumen(s) that are sized toreceive a conventional guidewire (typically 0.014″ diameter) or anyother suitable guidewire (e.g., having diameters between 0.018″ and0.032″) and the flexible proximal portion of the catheter body caninclude a short lumen (e.g., about 12 centimeters in length). Such aconfiguration moves the guidewire out of the rigid portion so as to notinterfere with the debulking assembly.

In other embodiments, however, the guidewire lumen may be disposedwithin or outside the flexible proximal portion of the catheter body andrun a longer or shorter length, and in fact may run the entire length ofthe flexible portion of the catheter body. The guidewire can be disposedwithin lumen on the flexible portion of the catheter body and exit thelumen at a point proximal to the rigid portion of the catheter. Theguidewire can then enter a proximal opening in the tip lumen and exit adistal opening in the tip lumen. In some embodiments, the catheter has adistal guidewire lumen on its flexible distal tip and a proximalguidewire lumen on its flexible body. For example, in some embodimentsthe distal lumen may have a length of between about 2.0 cm and about 3.0cm and the proximal lumen may have a length of between about 10 cm andabout 14 cm. In yet further embodiments, a distal tip guidewire lumenmay be configured to telescope within a proximal guidewire lumen, orvice versa. A telescoping guidewire lumen may enhance performance of thecatheter by preventing a guidewire from being exposed within a bodylumen.

The present invention may optionally employ any of a wide variety ofconventional radiopaque markers, imaging devices, and/or transducers. Inexemplary embodiments, the catheters of the present invention caninclude a radiopaque distal portion and/or radiopaque markers disposedon a distal portion of the catheter body, such as proximal and distal ofthe cutting window, on the cam or ramp, so as to allow the user to trackthe position of the cutter, or the like. The catheters of the presentinvention will also be particularly useful with ultrasonic transducers,such as an IVUS, of a type which may be deployed linearly within thecatheter body or circumferentially on the debulking assembly. Lineardeployment will allow viewing along a discrete length of the catheteraxis, preferably adjacent to the cutting point, usually over a length inthe range from 1 mm to 30 mm, preferably 2 mm to 10 mm.Circumferentially deployed phased arrays may subtend a viewing arc inthe range from 5° to 360°, usually from 180° to 360°. For imagingtransducers located on cutting blades within a housing or second cuttingelement, the field of imaging will generally be limited by thedimensions of the aperture. In some cases, however, it might be possibleto fabricate all or a portion of the cutter blade/housing out of anultrasonically translucent material. A more complete description ofsuitable imaging catheters are described more fully in U.S. patentapplication Ser. No. 09/378,224, filed Aug. 19, 1999, and entitled“Atherectomy Catheter with Aligned Imager,” now U.S. Pat. No., 6,299,622B1, the complete disclosure of which is incorporated herein byreference. In addition to ultrasonic array transducers, the imagingdevices of the present invention may comprise optical coherencetomography devices, such as described in U.S. Pat. No. 5,491,524, thefull disclosure of which is incorporated herein by reference, as well asHuang et al. (1991) Science 254:1178-1181; Brezinski et al. (1997) Heart77:397-403; and Brezinski et al (1996) Circulation 93:1206-1213. In someinstances, the present invention may also provide optical imaging usingoptical wave guides and the like.

Referring now to FIG. 1, a catheter 20 constructed in accordance withprinciples of the present invention comprises a catheter body 22 havinga proximal portion 24 and a distal portion 26. Proximal portion 24 canbe coupled to distal portion 26 with a connection assembly 27 to allowpivoting or deflection of distal portion 26 relative to proximal portion24. A proximal end of the catheter body 22 can have a handle 40 formanipulation by a user, a luer for connection to an aspiration or fluiddelivery channel, or the like.

A debulking assembly, such as a cutter 28, abrasive member, or the like,is disposed within a lumen 30 of the catheter body 22. The cutter 28 istypically rotatable within the distal portion 26 about an axis that isparallel to the longitudinal axis of the distal portion 26 of catheter20 and axially movable along the longitudinal axis. The cutter 28 canaccess target tissue through a side opening window 32 which is typicallylarge enough to allow the cutter 28 to protrude through and move out ofthe window 32 a predetermined distance. The cutter is coupled to acutter driver 34 through a coiled drive shaft 36. Actuation of a movableactuator or other input device 38 can activate the drive shaft 36 andcutter, move cutter 28 longitudinally over a cam so as to deflect thedistal portion and move the cutter 28 out of cutting window 32. Cammingof the cutter 28 can cause the distal portion 26 to pivot or deflectrelative to the proximal portion 24 so as to deflect and urge the cutterinto the tissue in the body lumen.

In some embodiments, the distal portion 26 of the catheter may be movedto an angled or offset configuration from the longitudinal axis of theproximal portion 24 of the catheter and the cutter 28. In someembodiments, the cutter 28 can also be deflected off of the axis of theproximal and/or distal portion of the catheter. Moving the distalportion 26 to an angled/offset position may cause a portion of thecatheter to urge against a target tissue, may expose the cutter 28through the window 32 or both, in various embodiments.

In catheters 20 of the present invention, proximal portion 24 istypically relatively flexible and distal portion 26 is typicallyrelatively rigid. Additionally, many embodiments include a flexibledistal tip 42. The flexible proximal portion 24 of the catheter istypically a torque shaft and the distal portion 26 is typically a rigidtubing. The torque shaft 24 facilitates transportation of the catheterbody 22 and cutter 28 to the diseased site. The proximal end of thetorque shaft 24 is coupled to a proximal handle 40 and the distal end ofthe torque shaft is attached to the distal, rigid portion 26 of thecatheter through the connection assembly 27. The drive shaft 36 ismovably positioned within the torque shaft 24 so as to rotate andaxially move within the torque shaft 24. The drive shaft 36 and torqueshaft 24 are sized to allow relative movement of each shaft withoutinterfering with the movement of the other shaft. The catheter body willhave the pushability and torqueability such that torquing and pushing ofthe proximal end will translate motion to the distal portion 26 of thecatheter body 22.

Referring now to FIG. 1A, a catheter 20 as in FIG. 1 may have a flexibleproximal portion 24 which additionally includes urging means 25. Asshown in FIG. 1A, urging means 25 may comprise a rigid bent or curvedshape towards the distal end of proximal portion 24, which may help urgethe cutter 28 or other debulking apparatus toward a wall of a body lumento enhance treatment. Such a rigid bend increases the working range ofthe catheter by allowing the cutter to be urged into a lumen wall acrossa wider diameter lumen.

In other embodiments, urging means 25 may take many other suitableforms. For example, a similar result to the rigid bend may be achievedby including a rigid distal portion that is not permanently bent butthat is more rigid on one side than on the opposite side of catheterbody 22. Thus, when proximal tension is applied to the proximal portion24, as when proximal force is applied to the debulking apparatus toexpose the cutter 28 through the window 32, the urging means 25 (i.e.,the rigid distal portion of proximal portion 24) will cause the catheterbody 22 to bend toward the less rigid side. The less rigid side willtypically be the same side as the window 32, so that the window 32and/or the cutter 28 will be urged against a wall of a body lumen by thebend. In still other embodiments, a shaped element may be introducedinto catheter body to act as urging means 25. Any suitable urging meansis contemplated.

FIG. 2 illustrates an exploded view of a distal end of the catheter. Insuch embodiments, the catheter 10 includes a connection assembly 27, arigid housing 26, a distal tip 42 that at least partially defines acollection chamber 53 for storing the severed atheromatous material, anda lumen that can receive the guidewire. The distal tip 42 can have adistal opening 43 that is sized to allow an imaging guidewire orconventional guidewire (not shown) to be advanced distally through thetip. In some embodiments, the distal tip 42 may also include a distalguidewire lumen (not shown) for allowing passage of a guidewire. Forexample, some embodiments may include a distal guidewire lumen having alength of between about 1.0 cm and about 5.0 cm, and preferably betweenabout 2.0 cm and about 3.0 cm. Such a distal guidewire lumen may be usedalone or in conjunction with a proximal guidewire lumen located onanother, more proximal, portion of the catheter 20.

In embodiments including a distal guidewire lumen and a proximalguidewire lumen, the distal lumen may be configured to partiallytelescope within a portion of the proximal guidewire lumen, or viceversa. Such telescoping lumens may be used in embodiments where thedistal portion 26 of catheter body 22 is movable relative to theproximal portion 24. A telescoping lumen may enhance performance of thecatheter 20 by allowing a guidewire to be maintained largely within alumen and to not be exposed within the body lumen being treated.Telescoping lumens may have any suitable diameters and configurations toallow for sliding or otherwise fitting of one lumen within another.

A ramp or cam 44 can at least partially fit within the distal portion26. As will be described in detail below, in many embodiments proximalmovement of the cutter 28 over the ramp 44, causes the deflection of thedistal housing 26 and guides cutter 28 out of cutting window 32. (Inother embodiments, a ramp may be used to deflect the distal portionwithout extending the cutter out of the window.) Attached to the ramp 44is a housing adaptor 46 that can connect one or more articulation member48 to the distal tip to create an axis of rotation of the distal portion26. The housing adaptor 46 and articulation member 48 allow the distalend of the catheter to pivot and bias against the body lumen. In theillustrated embodiment there are only one housing adaptor 46 and onearticulation member 48, but it should be appreciated that the cathetersof the present invention can include, two, three, or more joints (e.g.,axis of rotation), if desired. Moreover, the axes of rotation can beparallel or non-parallel with each other.

The catheter can also include a shaft adaptor 50 and collar 52 to couplearticulation member 48 to the torque shaft 22. Shaft adaptor 50 canconnect the housing to the torque shaft and collar 52 can be placed overa proximal end of the shaft adaptor and crimped for a secure attachment.It should be appreciated by one of ordinary skill in the art that thatwhile one exemplary catheter of the present invention has the abovecomponents that other catheters of the present invention may not includemore or fewer of the components described above. For example, somecomponents can be made integral with other components and somecomponents may be left out entirely. Thus, instead of having a separateramp 44, the ramp may be integrated with the distal tip to direct thecutter out of the cutting window.

As shown in FIGS. 3-5, the cutters 28 of the present invention willgenerally be movable between two or more positions. During advancementthrough the body lumen, the cutter will generally be in a neutralposition (FIGS. 3A and 3B) in which the cutter 28 is distal of cuttingwindow 32. In some embodiments, an imaging device (not shown) can becoupled to cutter 28 so as to image the body lumen through cuttingwindow 32 when cutter 28 is in the neutral position. Once the catheter20 has reached the target site, the cutter 28 can be moved to an openposition (FIGS. 4A and 4B) in which the cutter 28 is moved to a proximalend of the cutting window 32 and will extend out of the cutting window32 a distance L₁ beyond an outer diameter D of the rigid portion 26. Inmost embodiments, in the open position, the cutter will have deflectedthe distal portion and the cutter's axis of rotation will generally bein line with connection assembly 27 but angled or offset fromlongitudinal axis of the distal portion of the catheter body.

Optionally, in some embodiments, cutter 28 can be moved to a packingposition, in which the cutter is moved distally, past the neutralposition, so as to pack the severed tissue into a distal collectionchamber 53 (FIGS. 5A and 5B). It should be appreciated however, thatwhile the exemplary embodiment moves the cutter to the above describedpositions, in other embodiments of the present invention the cutter canbe positioned in other relative positions. For example, instead ofhaving the neutral position distal of the cutting window, the neutralposition may be proximal of the window, and the open position may bealong the distal end of the cutting window, or the like.

Referring again to FIGS. 4A and 4B, the interaction of the components ofthe rigid distal portions 26 in one exemplary embodiment of the presentinvention will be further described. As shown in FIG. 4B, the cuttingwindow 32 is typically a cutout opening in the distal portion 26. Whilethe size of the cutting window 32 can vary, the cutting window should belong enough to collect tissue and circumferentially wide enough to allowthe cutter to move out of the cutting window during cutting, but sizedand shaped to not expel emboli into the vasculature. Cams or ramp 44(shown most clearly in FIG. 4B) can be disposed in the distal portion ofthe catheter body to guide or otherwise pivot the cutter 28 out of thecutting window 32 as the cutter 28 is pulled proximally throughtensioning of drive shaft 36.

A joint is located proximal to the cutting window 32 to provide a pivotpoint for camming of the distal portion 26 relative to the proximalportion 24. The bending at a flexible joint 49 is caused by theinteraction of cams or ramps 44 with cutter 28 and the tensile forceprovided through drive shaft 36. In the exemplary configuration, thejoint includes a housing adaptor 46 that is pivotally coupled to thedistal rigid portion 26. As shown in FIGS. 4A and 4B, the resultingpivoting of the rigid distal portion 26 relative to the proximal portioncauses a camming effect which urges the distal housing against the bodylumen wall without the use of urging means (e.g., a balloon) that ispositioned opposite of the cutting window. Thus, the overall crosssectional size of the catheter bodies can be reduced to allow thecatheter to access lesions in smaller body lumens. In exemplaryembodiments, the distal housing can deflect off of the axis of theproximal portion of the catheter typically between 0° degrees and 30°degrees, usually between 5° degrees and 20° degrees, and most preferablybetween 5° degrees and 10° degrees. The angle of deflection relatesdirectly to the urge. Urge, however, does not necessarily relate toforce but more to the overall profile of the catheter. For example, thegreater the angle of deflection, the larger the profile and the biggerthe lumen that can be treated. The ranges were chosen to allow treatmentof vessels ranging from less than 2 mm to greater than 3 mm within thelimits of mechanical design of the components. It should be appreciatedhowever, that the angles of deflection will vary depending on the sizeof the body lumen being treated, the size of the catheter, and the like.

In some embodiments, the deflection of the distal portion 26 of thecatheter urges the cutter into position such that distal advancement ofthe entire catheter body can move the rotating cutter through theocclusive material. Because the cutter is moved a distance L₁ beyond theouter diameter of the distal portion of the catheter and outside of thecutting window, the user does not have to invaginate the tissue into thecutting window. In some embodiments, for example, the cutter can bemoved between about 0.025 mm and about 1.016 mm, and preferably betweenabout 0.025 mm and about 0.64 mm, beyond the outer dimension of thedistal housing. It should be appreciated that the cutter excursiondirectly relates to the depth of cut. The higher the cutter moves out ofthe cutting window the deeper the cut. The ranges are chosen aroundefficacy without risk of perforation of the body lumen.

Some embodiments of the catheter include a shuttle mechanism or othersimilar mechanism for temporarily locking the catheter in a cuttingposition. FIGS. 3C and 3D illustrate such an embodiment in the neutral,non-cutting position. Such embodiments generally include a shuttlemember 45 and a shuttle stop member 42. The shuttle stop member 42 istypically disposed at an angle, relative to a longitudinal axis throughthe catheter. FIGS. 4C and 4D show the same embodiment in the cuttingposition. When the cutter 28 is moved into the cutting position in suchembodiments, the shuttle member 45 falls into the shuttle stop member 42and thus locks the debulking apparatus in a cutting position. To unlockthe debulking apparatus, the cutter 28 may be advanced forward,distally, to release the shuttle member 45 from the shuttle stop member42.

Some embodiments including a shuttle mechanism will also include twojoints in catheter body 22. Thus, catheter body 22 will include aproximal portion 26, a distal portion 24 and a middle portion. Whenshuttle mechanism is activated to expose cutter 28 through window 32,the middle portion may orient itself at an angle, relative to theproximal and distal portions, thus allowing cutter to be urged towards aside of a lumen. Such a two-jointed configuration may provide enhancedperformance of the catheter 20 by providing enhanced contact of thecutter 28 with material to be debulked from a body lumen.

Pushing the entire catheter across a lesion removes all or a portion ofthe lesion from the body lumen. Severed tissue from the lesion iscollected by directing it into a collection chamber 53 in the tip viathe cutter 28. Once the catheter and cutter 28 have moved through thelesion, the cutter 28 can be advanced distally to a “part off position”in which the cutter is moved back into the cutting window 32 (FIG. 3B).The tissue is collected as the severed pieces of tissue are directedinto a collection chamber 53 via the distal movement of cutter 28 andcatheter. The collection chamber 53 of the tip and distal portion 26acts as a receptacle for the severed material, to prevent the severedocclusive material from entering the body lumen and possibly causingdownstream occlusions. The cutter 28 can interact with the distal edgeof the cutting window to part off the tissue and thereafter pack thesevered tissue into collection chamber 53 (FIG. 3B). In exemplaryembodiments, the driver motor can be programmed to stop the rotation ofthe cutter at the part off position so that the cutter 28 can move to athird position (FIG. 5B) and pack the material in the collection chamberin the tip without rotation. Typically, the collection chamber 53 willbe large enough to allow multiple cuts to be collected before the devicehas to be removed from the body lumen. When the collection chamber isfull, or at the user's discretion, the device can be removed, emptiedand reinserted over the guidewire via a monorail system, as will bedescribed below.

In various embodiments, enhancements to the collection chamber 53 may beincluded. For example, in some embodiments the collection chamber 53 maybe configured to be partially or completely translucent or radiolucentand a portion of the catheter surrounding or adjacent to the window 32will be radiopaque. This combination of radiolucent collection chamber53 and radiopaque material adjacent window 32 will enhance the abilityof a user to determine how full the collection chamber 53 is, becausethe fullness of the collection chamber will be directly related to thedistance the cutter 28 can advance forward into the collection chamber53. By facilitating the assessment of collection chamber filling, theseembodiments will reduce the need for manually withdrawing the catheterto examine the collection chamber 53.

In some embodiments, the collection chamber 53 may connect to the rigidhousing by means of interlocking components, which interlock withcomplementary components on the rigid housing. Such components mayresemble a screw-in configuration, for example. Interlocking componentswill provide a stable connection between the collection chamber 53 andthe rigid housing while not increasing the outer diameter of either thechamber 53 or the housing. Generally, collection chamber 53 may be givenany suitable configuration, shape or size. For example, collectionchamber 53 in FIGS. 6-8 has a helical configuration. Alternatively,collection chamber 53 may include a series of circular members, straightlinear members, one solid cylindrical or cone-shaped member or the like.

FIGS. 6 through 8 illustrate one exemplary monorail delivery system toassist in positioning the cutter 28 at the target site. For example, tip42 of the catheter can include a lumen 54 having a distal opening 43 anda proximal opening 55 that is sized to receive a guidewire, having adiameter of about 0.014 in., about 0.018 in., about 0.032 in. or anyother suitable diameter.

As shown in FIG. 8, the flexible proximal portion of the catheter bodymay also include a short lumen 56 (e.g., about 12 centimeters inlength). In some embodiments, however, the guidewire lumen 56 may bedisposed within or outside the flexible proximal portion of the catheterbody and run a longer or shorter length, and in fact may run the entirelength of the flexible portion 24 of the catheter body. In use, theguidewire can be disposed within lumen 56 on the flexible portion of thecatheter body and exit the lumen at a point proximal to the rigidportion 26 of the catheter. The guidewire can then re-enter a proximalopening 55 in the tip lumen 54 and exit through distal opening 43 in thetip lumen. By moving the guidewire outside of the rigid portion 26 ofthe catheter body, the guidewire will be prevented from tangling withthe cutter 28. Typically, tip lumen 54 will be disposed along a bottomsurface of the tip and the lumen 56 will be disposed along a side of theproximal portion 22 of the catheter body so that the guidewire will bein a helical configuration. In various embodiments, the tip lumen 54 andthe proximal lumen 56 can have any suitable combination of lengths. Forexample, in one embodiment the tip lumen 54 may have a length betweenabout 1 cm and about 5 cm, more preferably between about 2 cm and about3 cm, and the proximal lumen may have a length of between about 8 cm andabout 20 cm, more preferably between about 10 cm and about 14 cm.

Referring now to FIGS. 22A and 22B, some catheters 120 of the presentinvention include a proximal guidewire lumen 126 coupled with theproximal portion of the catheter body 123, and a telescoping distalguidewire lumen 124 coupled with either the distal tip 122, part of thedistal portion of the catheter body, or both. The telescoping lumen 124will typically be attached to the tip 122 or a distal portion, but willalso include an unattached portion 121, which will not be directlyattached to any part of the catheter body. This unattached portion 121(or “free floating lumen”) protects a guidewire from contacting a bodylumen in which the device is used and also allows the device to be movedmore freely, without bending or kinking the guidewire. The telescopingguidewire 124 extends within the proximal lumen 126 at the distalopening 127 of proximal lumen 126. Again, the telescoping feature allowsfor movement of the catheter body while preventing or reducing bendingof the guidewire. For example, in some embodiments catheter 120 allowsfor deflection of distal tip 122 and the distal portion of the catheter120 relative to the proximal portion 123, for example by movement abouta pivot point 129. Telescoping distal lumen 124 and proximal lumen 126allow for this movement by allowing distal lumen 124 to telescope withinproximal lumen 126. At the same time, distal lumen 124 protects a guidewire from exposure to a body lumen and/or bodily fluids.

Any suitable configurations and sizes of distal lumen 124 and proximallumen 126 are contemplated. For example, in one embodiment distal lumen124 may telescope within proximal lumen 126 by a distance ofapproximately 1 cm. Furthermore, a telescoping lumen 124 may be longerthan distal lumens in other embodiments. For example, telescoping lumen124 may have a length of between about 2 cm and about 10 cm, andpreferably between about 5 cm and about 8 cm. As is apparent from thedrawing figures, the outer diameter of telescoping distal lumen 124 isconfigured to fit within the inner diameter of proximal lumen 126.Generally, any combination of sizes, lengths, diameters and shapes ofdistal lumen 124 and proximal lumen 126 may be used, to allowtelescoping of one into another.

The catheters of the present invention can include radiopaque markers soas to allow the user to track the position of the catheter underfluoroscopy. For example, as already described, a point or area aroundor adjacent to the window may be made radiopaque. In other embodiments,the rigid distal portion 26 can be radiopaque and radiopaque markers canbe disposed on the flexible shaft. Typically, the markers 59 will bedisposed along the top, proximal to the cutting window, and on thebottom of the catheter to let the user know the position of the cutterand cutting window relative to the target site. If desired, the top andbottom markers can be different shaped so as to inform the user of therelative orientation of the catheter in the body lumen. Because theguidewire will form a helix in its transition from lumen 56 to tip lumen54, the user will be able to view the top and bottom radiopaque markers59 without interference from the guidewire. Some embodiments of thecatheter can also include a radiopaque cutter stop 61 (FIG. 3B) that iscrimped to driveshaft 36 proximal of the cutter that moves with thecutter so as to let the user know when the cutter is in the openposition.

FIGS. 9A through 11D show some exemplary embodiments of the cutter 28 ofthe present invention. The distal portion 60 of the rotatable cutter 28can include a serrated knife edge 62 or a smooth knife edge 64 and acurved or scooped distal surface 66. The distal portion 60 may have anysuitable diameter or height. In some embodiments, for example, thediameter across the distal portion 60 may be between about 0.1 cm andabout 0.2 cm. A proximal portion 68 of the cutter 28 can include achannel 70 that can be coupled to the drive shaft 36 that rotates thecutter. As shown in FIGS. 10A-10C, some embodiments of the cutters caninclude a bulge or bump 69 that is provided to interact with a stent soas to reduce the interaction of the cutting edge with the stent. In anyof the foregoing embodiments, it may be advantageous to construct aserrated knife edge 62, a smooth knife edge 64, or a scooped distalsurface 66 out of tungsten carbide.

Another embodiment of a cutter 28 suitable for use in the presentinvention is shown in side view within a catheter body distal portion 26in FIG. 11D. In this embodiment, the cutter 28 has a beveled edge 64,made of tungsten carbide, stainless steel, titanium or any othersuitable material. The beveled edge 64 is angled inward, toward the axisof rotation (or center) of the cutter 28, creating a “negative angle ofattack” 65 for the cutter 28. Such a negative angle of attack may beadvantageous in many settings, when one or more layers of material aredesired to be debulked from a body lumen without damaging underlyinglayers of tissue. Occlusive material to be removed from a vesseltypically has low compliance and the media of the vessel (ideally to bepreserved) has higher compliance. A cutter 28 having a negative angle ofattack may be employed to efficiently cut through material of lowcompliance, while not cutting through media of high compliance, byallowing the high-compliance to stretch over the beveled surface ofcutter 28.

FIGS. 12 through 16 illustrate an exemplary cutter driver 34 of thepresent invention. As shown in FIG. 12 and 13, cutter driver 34 can actas the handle for the user to manipulate the catheters 20 of the presentinvention as well as a power source. Typically, the cutter drivers 34 ofthe present invention include a single input device, such as a lever 38that controls the major operations of the catheter (e.g., axial movementto cause urging, rotation to cause cutting, and axial movement forpacking). As shown in FIGS. 13 and 14, cutter driver 34 includes a powersource 72 (e.g., batteries), a motor 74, a microswitch 76 for activatingmotor 74, and a connection assembly (not shown) for connecting the driveshaft 36 to the driver motor 74. In some embodiments, the drive motorcan rotate drive shaft 36 between 1,000 rpm and 10,000 rpm or more, ifdesired.

FIGS. 14 through 16 illustrate one exemplary method of operating cutterdriver 34. In use, the catheter will be delivered to the target sitewith cutter driver unattached and the cutter in the neutral position(FIG. 3B). The cutter driver can be attached with the urge lever 38 in aneutral position (FIG. 14), which indicates that the cutter is closed,but not in a packing position. The user can then move the catheter (andcutter driver unit, if desired) to position the distal portion 26 of thecatheter adjacent the target tissue. As shown in FIG. 15, to activatethe rotation of the cutter, the urge lever 38 can be moved proximallyfrom the neutral position to move the cutter proximally and out ofcutting window 32 (FIG. 4B) and simultaneously depressing microswitch 76to activate motor 74. At the end of the cutting procedure, as shown inFIG. 16, the user can push urge lever 38 completely forward to a distalposition to push the cutter into a packing position (FIG. 5B). After theurge lever passes the middle of the travel, the microswitch 76 can bereleased so as to deactivate the cutter before reaching the packingposition such that packing can occur without the cutter rotating. Itshould be appreciated, while the figures illustrate the use of an urgelever or thumb switch as an input device, the present invention can useother type of input devices, such as labeled buttons (e.g., closewindow, debulk tissue, and pack), or the like.

Advantageously, cutter driver 34 provides an automatic on/off control ofthe cutter 28 that is keyed to the position of the cutter. Such aconfiguration frees the user from the complicated task of rememberingthe sequence of operations to activate and deactivate the rotation andaxial movement of the cutter.

While the cutter driver 34 is illustrated as a disposable batterypowered unit, it should be appreciated that in other embodiments, thecutter driver can use other power sources to control the cutter driver.It should further be appreciated that other cutter drivers can be usedwith the present invention. While not preferred, it is possible to haveseparate controls to control the axial movement of the cutter and therotation of the cutter.

Some exemplary methods of the present invention will now be described.One method of the present invention comprises delivering a catheter to atarget site in the body lumen. A distal portion of the catheter can bedeflected relative to a proximal portion of the catheter to expose atissue debulking device in the catheter. The body lumen can be debulkedwith the exposed debulking device. Specifically, as shown schematicallyin FIG. 17, one specific method comprises advancing a catheter to atarget site (Step 100). A cutter can be rotated and moved out of thecutting window (Steps 102, 104). Preferably, a distal portion of thecatheter can be pivoted or deflected so as to position the cutteradjacent the target material. Thereafter, the catheter and the rotatingcutter can be moved through the body lumen to remove the target materialfrom the body lumen (Step 106).

As shown in FIGS. 18 and 19, the catheter can be percutaneously advancedthrough a guide catheter or sheath and over a conventional or imagingguidewire using conventional interventional techniques. The debulkingcatheter 20 can be advanced over the guidewire and out of the guidecatheter to the diseased area. As shown in FIG. 18, the window 32 willtypically be closed (with the cutter or other debulking device 28 in afirst, distal position). As shown in FIG. 19, catheter 20 will typicallyhave at least one hinge or pivot connection to allow pivoting about oneor more axes of rotation to enhance the delivery of the catheter intothe tortuous anatomy without dislodging the guide catheter or othersheath. The cutter can be positioned proximal of the lesion. Optionally,a transducer, IVUS, or other imaging assembly can be used to verify theposition of the debulking catheter.

Once the position of the catheter is confirmed, the cutter 28 will beretracted proximally and moved out of cutting window 32 to its second,exposed position. In some embodiments, movement of the cutter candeflect the distal portion of the catheter to increase the profile ofthe catheter at the target site. Movement of the cutter is typicallycaused by proximal movement of lever 38 and tensioning of drive shaft36. Movement of the lever can be scaled to any desired ratio or a direct1:1 ratio of movement between the handle and cutter. When the cutter ismoved proximally it contacts ramp or cam surfaces so as to guide thecutter up and at least partially out of the cutting window 32.Additionally, as shown by arrow 80, the distal portion of catheter body26 rotates about the joint 49 to provide an urging force for the cutter(and catheter body) to move toward the diseased area.

Thereafter, as shown by arrow 82 the operator can move the entirecatheter body 22 through the lesion to dissect the tissue. As the cutter28 and catheter body 22 are advanced distally through the lesion, tissuethat is trapped between the cutting edge 52 and the cutting window 32 issevered from the body lumen. To part off the tissue, the operator canstop pushing the device distally and the cutter can be advanced distallyinside the cutting window by advancing the handle 38. During the distalmovement of the cutter, the cutter 28 rides back over the ramps 44 anddirects the cutter back inside of the cutting window 32. Such movementcauses the distal portion 26 of the catheter to move in line with thecutter and proximal portion 24 (FIG. 5B). When the cutter has moved toits distal position, the cutter parts off the severed tissue and urgesthe severed tissue inside of a collection chamber 53 in the distal tip42. Optionally, after the cutter 28 has parted off the tissue, the lever38 and thus the non-rotating cutter 38 can be advanced distally to packthe tissue into the collection chamber 53 (FIG. 5B). Use of the cutterto pack the severed tissue will allow the operator multiple specimens tobe collected prior to removing the catheter 20 from the body lumen. Whenit is determined that the collection chamber is fill, the catheter canbe removed from the body lumen and the collection chamber can beemptied.

In another method of the present invention, as shown in FIG. 20, aninput device is disposed in a first position to position a tissueremoval element in a neutral position (Step 120). The input device isactivated to rotate the tissue removal element and to axially move thetissue removal device to an active position (Step 122). The input devicecan then be activated again to move the tissue removal element to apacking position (Step 124). In an exemplary embodiment, the inputdevice is a lever or thumb switch that can be moved to correspond to themovement of a cutting element on the catheter. Thus, as the lever ismoved proximally, the cutter is rotated and moved proximally to an openposition. When the lever is moved to a distal position, the rotation ofthe cutter can be stopped and the cutter can be moved distally to packsevered tissue into a collection chamber.

Referring to FIGS. 21-24, still another device 102 for cutting and/orremoving material is shown. The device 102 has a cutting element 104which may be any suitable cutting element 104 such as those describedherein. The device 102 has an elongate body 106 and a visualizationelement 114 coupled to the body 106. A cover or tip 108 is positioned atthe distal end of the device 102. The cover 108 is movable from thestored position of FIGS. 21 and 22 to the working position of FIG. 23 inwhich at least part of the cutting element 104 is exposed

The cover 108 may be movable relative to the elongate body 106 in anysuitable manner. For example, the cover 108 and body 106 may engage oneanother with a slot and pin engagement 107 so that the cover 108translates linearly relative to the body 106. The cover 108 may benaturally biased or held in the stored position with the user actuatingthe device to move the cover 108 to the working position. For example,the cover 108 may be coupled to a lumen 110, such as a guidewire lumen,with the user tensioning, or even compressing, the lumen 110 and/or body106 to move the cover 108 to the working position. The cover 108 has alongitudinal axis which may remain substantially parallel to thelongitudinal axis of the elongate body 106. Furthermore, the cover 108may be movable to a number of different positions which expose varyingamounts of the cutting element 104 so that the depth of cut may beselected or varied by the user. The cover or tip 108 may have a recessor cavity 112 in which material to be removed is held as is describedherein.

The visualization element 114 may be any suitable visualization elementsuch as a fiberoptic and lens or an ultrasound element. Thevisualization element 114 may be movable or fixed relative to the body106. The visualization element 114 is positioned on a radially outer,and preferably outermost, portion of the body 106 so that the element114 may be pressed against or moved adjacent to the tissue of interest.This may provide advantages when using certain types of visualizationelements 114 such as optical elements which may emit or receive energywhich is partially absorbed by blood or other fluids present. Variousexamples of a suitable visualization element are described in U.S. Pat.Nos. 6,191,862, 6,445,939, 6,134,003, 5,459,570 and 5,321,501 which arehereby incorporated by reference.

Referring to FIGS. 24 and 25, still another device 130 for cuttingand/or removing material is shown wherein the same or similar referencenumbers refer to the same or similar structure. The device 130 may beused to cut or remove material from a vascular location using any methoddescribed herein. The device 130 has the cutting element 104 which maybe coupled to the torque transmitting element extending through theelongate body 106. A first pivot point 132 and a second pivot point 134are positioned on opposite sides of the cutting element 104. When movingto the working position of FIG. 25, the cutting element 104 moves intoengagement with the tissue to be cut or removed. The device 130 may alsohave the visualization element 114 positioned on the radially outermostpart of the device 130. The visualization element may be moved from thestored position of FIG. 24 to the working position of FIG. 25. Thedevice 130 has a tip 135 which has a recess or cavity 112 or otherstructure to receive material to be removed. The device 130 may benaturally biased toward the working or stored position with the otherposition being created by tensioning a pull wire 137 on one or the otherside of the device 130.

Referring to FIGS. 26A and 26B, another device 140 is shown having anelongate body 142 which is deformable to a generally helical shape. Theelongate body 142 is moved to the deformed or helical shape to helpstabilize the device 140 within the vessel. Stabilization of the device140 may be particularly helpful when moving the entire device 140through the vessel when removing material as described herein. Thehelical shape of the body may help to stabilize the device, dependingupon the particular shape of the vasculature, and may specifically helpresist or reduce twisting of the device 140 within the vasculature asthe device is advanced during cutting. The helical shape may be formedin any suitable manner. Referring to FIGS. 27A and 27B, for example, atube 144 may be cut with a pattern which naturally forms the helicalshape when a compressive force is applied to the tube 144. The tube 144is contained in a sheath 146 which holds the tube 144 but permits thetube 144 to deform as necessary. As can be appreciated from FIGS. 26Aand 26B, the helical shape may be somewhat subtle. Surface lines 145have been added for clarity in visualizing the shape of the body 142. Inone embodiment, the diameter of the body 142 is 1.0 to 2.5 mm while thediameter of the helical shape is about 2.0 to 7.5 mm. In still anotheraspect, the helical shape has less than 360 degrees of rotation overit's length and preferably about 180 degrees. The deformed part of theelongate body 142, 152 may be relatively long. For example, the deformedpart may be at least 1 cm and may even be at least 2 cm when measured ina relaxed or straightened configuration. Of course, the elongate body142 which may also be deformed to a generally S-shape rather thanhelical shape.

The shaft or body of FIGS. 26A and 26B may be used with any of thedevices or methods described herein. For example, the helical body 142may be used with the device 102 of FIGS. 21-23. Initial compression ofthe tube 144 may cause the body 142 to assume the helical shape.Continued compression of the tube 144 displaces the tip or cover 108 toexpose the cutting element. The entire device 102 may then be movedthrough the vessel to cut a continuous piece of material which isdirected into the recess or cavity 112 in the cover 108. Thus, it can beappreciated that many combinations are within the scope of the presentinvention with any of the working ends of the device being used with anyof the shafts or elongate bodies.

Referring now to FIG. 28, the present invention will further comprisekits including catheters 200, instructions for use 202, and packages204. Catheters 200 will generally be as described above, and theinstruction for use (IFU) 202 will set forth any of the methodsdescribed above. Package 204 may be any conventional medical devicepackaging, including pouches, trays, boxes, tubes, or the like. Theinstructions for use 202 will usually be printed on a separate piece ofpaper, but may also be printed in whole or in part on a portion of thepackaging 204.

While all the above is a complete description of the preferredembodiments of the inventions, various alternatives, modifications, andequivalents may be used. For example, while preferred cutters are movedproximally to move the cutter out of the cutting window, alternativeembodiments may move the cutter distally to move the cutter out of thecutting window. Additionally, while most embodiments employ a cutterthat extends out beyond the outer diameter of the cutting window, it maybe possible to incorporate a cutter that stays within the diametercatheter body. Additionally, in some embodiments, the debulking assemblymay be exposed through the window without causing a deflection of thedistal portion of the catheter. Moreover, instead of having a distal tipthat is rotatable relative to the proximal portion of the catheter, thecatheter can include a shape memory material such that the catheterforms a jog or a pre-bent shape when it reaches its target area.

Although the foregoing invention has been described in detail forpurposes of clarity of understanding, it will be obvious that certainmodifications may be practiced within the scope of the appended claims.

1. A method of removing material from a vascular location, comprisingthe steps of: providing a cutting device having an elongate body and arotatable cutting element, the elongate body having an opening therein,the rotatable cutting element being coupled to a torque transmittingelement which extends through the elongate body, the elongate bodyhaving a deformable portion located proximal of the cutting element;advancing the cutting device through a patient's vascular system, thecutting element being in a stored position in which the cutting elementis not exposed; withdrawing the cutting element proximally with respectto the elongate body after the advancing step to move the cuttingelement from the stored position to a working position and to deform thedeformable portion, the deformable portion being deformed toward apredetermined deformed position; and moving the cutting element and theopening through the vascular system with the cutting element being inthe working position and while the deformable portion is deformed towardthe predetermined deformed position, wherein at least part of therotatable cutting element is exposed to cut tissue when in the workingposition, the cut tissue being directed through the opening when thecutting element and opening are moved through the vascular system. 2.The method of claim 1, wherein: the withdrawing step is carried out withthe predetermined deformed position being S-shaped.
 3. The method ofclaim 1, wherein: the providing step is carried out with the elongatebody having a first pivot point and a second pivot point, the first andsecond pivot points being positioned on opposite sides of the cuttingelement.
 4. The method of claim 1, wherein: the withdrawing step iscarried out with the predetermined deformed position being a helicalshape.
 5. The method of claim 4, wherein: the withdrawing step iscarried out with the helical shape having a diameter of about 2.0 to 7.5mm and the elongate body has an outer diameter of about 1.0 to 2.5 mm.6. The method of claim 4, wherein: the withdrawing step is carried outwith the deformable portion having a length of at least 1 cm.
 7. Amethod of removing material from a vascular location, comprising thesteps of: providing a cutting device having an elongate body and arotatable cutting element, the elongate body having an opening and acollection chamber positioned distal to the opening, the rotatablecutting element being coupled to a torque transmitting element whichextends through the elongate body, the elongate body having a deformableportion; advancing the cutting device through a patient's vascularsystem, the cutting element being in a stored position in which thecutting element is not exposed; deforming the deformable portion afterthe advancing step by moving the cutting element in a proximal directionwith respect to the elongate body from the stored position to a workingposition, the deformable portion being deformed toward a predetermineddeformed position; and moving the cutting element and the opening in adistal direction through the vascular system with the cutting elementbeing in the working position and while the deformable portion isdeformed toward the predetermined deformed position, wherein at leastpart of the rotatable cutting element is exposed to cut tissue when inthe working position, the cut tissue being directed through the openingand into the collection chamber when the cutting element and opening aremoved in the distal direction through the vascular system.
 8. The methodof claim 7, wherein: the moving step is carried out with thepredetermined deformed position being S-shaped.
 9. The method of claim7, wherein: the providing step is carried out with the elongate bodyhaving a first pivot point and a second pivot point, the first andsecond pivot points being positioned on opposite sides of the cuttingelement.
 10. The method of claim 7, wherein: the deforming step iscarried out with the predetermined deformed position being a helicalshape.
 11. The method of claim 10, wherein: the deforming step iscarried out with the helical shape having a diameter of about 2.0 to 7.5mm and the elongate body has an outer diameter of about 1.0 to 2.5 mm.12. The method of claim 10, wherein: the deforming step is carried outwith the deformable portion having a length of at least 1 cm.